Add RDRAND_RNG

For those that are willing to trust uninspectible hardware. :)

Changes RDRAND entropy source to call RDRAND_RNG

Add --rdrand flag to rng cmdlet

2 files changed, 9 insertions, 39 deletions

diff --git a/src/lib/entropy/rdrand/info.txt b/src/lib/entropy/rdrand/info.txt
index e3e1a2a50..ebc7fb747 100644
--- a/src/lib/entropy/rdrand/info.txt
+++ b/src/lib/entropy/rdrand/info.txt
@@ -1,6 +1,8 @@
 define ENTROPY_SRC_RDRAND 20131128
 
-need_isa rdrand
+<requires>
+rdrand_rng
+</requires>
 
 <source>
 rdrand.cpp
@@ -9,15 +11,3 @@ rdrand.cpp
 <header:internal>
 rdrand.h
 </header:internal>
-
-<arch>
-x86_32
-x86_64
-</arch>
-
-<cc>
-gcc
-clang
-icc
-msvc
-</cc>
diff --git a/src/lib/entropy/rdrand/rdrand.cpp b/src/lib/entropy/rdrand/rdrand.cpp
index fb04d7b78..7fa05c605 100644
--- a/src/lib/entropy/rdrand/rdrand.cpp
+++ b/src/lib/entropy/rdrand/rdrand.cpp
@@ -7,40 +7,20 @@
 */
 
 #include <botan/internal/rdrand.h>
+#include <botan/rdrand_rng.h>
 #include <botan/cpuid.h>
 #include <botan/build.h>
 
-#if !defined(BOTAN_USE_GCC_INLINE_ASM)
-  #include <immintrin.h>
-#endif
-
 namespace Botan {
 
 size_t Intel_Rdrand::poll(RandomNumberGenerator& rng) {
-   if(CPUID::has_rdrand())
+   if(CPUID::has_rdrand() && BOTAN_ENTROPY_INTEL_RNG_POLLS > 0)
       {
-      for(size_t p = 0; p != BOTAN_ENTROPY_INTEL_RNG_POLLS; ++p)
-         {
-         for(size_t i = 0; i != BOTAN_ENTROPY_RDRAND_RETRIES; ++i)
-            {
-            uint32_t r = 0;
-
-#if defined(BOTAN_USE_GCC_INLINE_ASM)
-            int cf = 0;
+      RDRAND_RNG rdrand_rng;
+      secure_vector<uint8_t> buf(4 * BOTAN_ENTROPY_INTEL_RNG_POLLS);
 
-            // Encoding of rdrand %eax
-            asm(".byte 0x0F, 0xC7, 0xF0; adcl $0,%1" :
-                "=a" (r), "=r" (cf) : "0" (r), "1" (cf) : "cc");
-#else
-            int cf = _rdrand32_step(&r);
-#endif
-            if(1 == cf)
-               {
-               rng.add_entropy_T(r);
-               break;
-               }
-            }
-         }
+      rdrand_rng.randomize(buf.data(), buf.size());
+      rng.add_entropy(buf.data(), buf.size());
       }
 
    // RDRAND is used but not trusted